Hey Michael so depending on the OS that you have installed on your phone you can add different languages.

To check how many languages are available to you, connect your BlackBerry device to your computer and open up the Desktop Manager on your PC. If you don't have the Desktop Manager installed on your computer, visit BlackBerry - BlackBerry Desktop Software to download it.

Once your phone connects to the DM, click Applications.

After the list of currently installed apps loads onto the DM, click Add Applications and you will see a menu of all available languages that can be installed on your device.

Simply check the boxes of the languages you would like to add and proceed from there.

I was wondering the same thing. I have a Pearl 8100 and Curve 8310 that I will bring to Indonesia and most lend to friends there who don't speak/read English. I have used the DM and have uninstalled/installed several OS packages looking for an option for Indonesian and had no luck.